Commit 7ca801d ("[efi] Use the EFI_RNG_PROTOCOL as an entropy source
if available") added EFI_RNG_PROTOCOL as an alternative entropy source
via an ad-hoc mechanism specific to efi_entropy.c.
Split out EFI_RNG_PROTOCOL to a separate entropy source, and allow the
entropy core to handle the selection of RDRAND, EFI_RNG_PROTOCOL, or
timer ticks as the active source.
The fault detection logic added in commit a87537d ("[efi] Detect and
disable seriously broken EFI_RNG_PROTOCOL implementations") may be
removed completely, since the failure will already be detected by the
generic ANS X9.82-mandated repetition count test and will now be
handled gracefully by the entropy core.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
As noted in commit 3c83843 ("[rng] Check for several functioning RTC
interrupts"), experimentation shows that Hyper-V cannot be trusted to
reliably generate RTC interrupts. (As noted in commit f3ba0fb
("[hyperv] Provide timer based on the 10MHz time reference count
MSR"), Hyper-V appears to suffer from a general problem in reliably
generating any legacy interrupts.) An alternative entropy source is
therefore required for an image that may be used in a Hyper-V Gen1
virtual machine.
The x86 RDRAND instruction provides a suitable alternative entropy
source, but may not be supported by all CPUs. We must therefore allow
for multiple entropy sources to be compiled in, with the single active
entropy source selected only at runtime.
Restructure the internal entropy API to allow a working entropy source
to be detected and chosen at runtime.
Enable the RDRAND entropy source for all x86 builds, since it is
likely to be substantially faster than any other source.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
AArch64 kernels tend to be distributed as gzip compressed images.
Enable IMAGE_GZIP by default for AArch64 to avoid the need for
uncompressed images to be provided.
Originally-implemented-by: Alessandro Di Stefano <aleskandro@redhat.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE currently assumes that DMA-capable devices can directly address
physical memory using host addresses. This assumption fails when
using an IOMMU.
Define an internal DMA API with two implementations: a "flat"
implementation for use in legacy BIOS or other environments in which
flat physical addressing is guaranteed to be used and all allocated
physical addresses are guaranteed to be within a 32-bit address space,
and an "operations-based" implementation for use in UEFI or other
environments in which DMA mapping may require bus-specific handling.
The purpose of the fully inlined "flat" implementation is to allow the
trivial identity DMA mappings to be optimised out at build time,
thereby avoiding an increase in code size for legacy BIOS builds.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
IPv6 PXE was included in the UEFI specification over eight years ago,
specifically in version 2.3 (Errata D).
http://www.uefi.org/sites/default/files/resources/UEFI_Spec_2_3_D.pdf
When iPXE is being chainloaded from a UEFI firmware performing a PXE
boot in an IPv6 network, it is essential that iPXE supports IPv6 as
well.
I understand that the reason for NET_PROTO_IPV6 being disabled by
default (in src/config/general.h) is that it would cause certain
space-constrained build targets to become too large. However, this
should not be an issue for EFI builds.
It is also worth noting that RFC 6540 makes a clear recommendation
that IPv6 support should not be considered optional.
https://tools.ietf.org/html/rfc6540
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Tore Anderson <tore@fud.no>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some UEFI BIOSes (observed with at least the Insyde UEFI BIOS on a
Microsoft Surface Go) provide a very broken version of the
UsbMassStorageDxe driver that is incapable of binding to the standard
EFI_USB_IO_PROTOCOL instances and instead relies on an undocumented
proprietary protocol (with GUID c965c76a-d71e-4e66-ab06-c6230d528425)
installed by the platform's custom version of UsbCoreDxe.
The upshot is that USB mass storage devices become inaccessible once
iPXE's native USB host controller drivers are loaded.
One possible workaround is to load a known working version of
UsbMassStorageDxe (e.g. from the EDK2 tree): this driver will
correctly bind to the standard EFI_USB_IO_PROTOCOL instances exposed
by iPXE. This workaround is ugly in practice, since it involves
embedding UsbMassStorageDxe.efi into the iPXE binary and including an
embedded script to perform the required "chain UsbMassStorageDxe.efi".
Provide a native USB mass storage driver for iPXE, allowing USB mass
storage devices to be exposed as iPXE SAN devices.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The only remaining use case in iPXE for the CPU direction flag is in
__memcpy_reverse() where it is set to allow the use of "rep movsb" to
perform the memory copy. This matches the equivalent functionality in
the EDK2 codebase, which has functions such as InternalMemCopyMem that
also temporarily set the direction flag in order to use "rep movsb".
As noted in commit d2fb317 ("[crypto] Avoid temporarily setting
direction flag in bigint_is_geq()"), some UEFI implementations are
known to have buggy interrupt handlers that may reboot the machine if
a timer interrupt happens to occur while the direction flag is set.
Work around these buggy UEFI implementations by using the
(unoptimised) generic_memcpy_reverse() on i386 or x86_64 UEFI
platforms.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide access to local files via the "file://" URI scheme. There are
three syntaxes:
- An opaque URI with a relative path (e.g. "file:script.ipxe").
This will be interpreted as a path relative to the iPXE binary.
- A hierarchical URI with a non-network absolute path
(e.g. "file:/boot/script.ipxe"). This will be interpreted as a
path relative to the root of the filesystem from which the iPXE
binary was loaded.
- A hierarchical URI with a network path in which the authority is a
volume label (e.g. "file://bootdisk/script.ipxe"). This will be
interpreted as a path relative to the root of the filesystem with
the specified volume label.
Note that the potentially desirable shell mappings (e.g. "fs0:" and
"blk0:") are concepts internal to the UEFI shell binary, and do not
seem to be exposed in any way to external executables. The old
EFI_SHELL_PROTOCOL (which did provide access to these mappings) is no
longer installed by current versions of the UEFI shell.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow the UEFI platform firmware to provide drivers for unrecognised
devices, by exposing our own implementation of EFI_USB_IO_PROTOCOL.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Abstract out the ability to reboot the system to a separate reboot()
function (with platform-specific implementations), add an EFI
implementation, and make the existing "reboot" command available under
EFI.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The EFI_CPU_IO_PROTOCOL is not available on all EFI platforms. In
particular, it is not available under OVMF, as used for qemu.
Since the EFI_CPU_IO_PROTOCOL is an abomination of unnecessary
complexity, banish it and use raw I/O instead.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
ANS X9.82 specifies several Approved Sources of Entropy Input (SEI).
One such SEI uses an entropy source as the Source of Entropy Input,
condensing each entropy source output after each GetEntropy call.
This can be implemented relatively cheaply in iPXE and avoids the need
to allocate potentially very large buffers.
(Note that the terms "entropy source" and "Source of Entropy Input"
are not synonyms within the context of ANS X9.82.)
Use the iPXE API mechanism to allow entropy sources to be selected at
compilation time.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The block device interface used in gPXE predates the invention of even
the old gPXE data-transfer interface, let alone the current iPXE
generic asynchronous interface mechanism. Bring this old code up to
date, with the following benefits:
o Block device commands can be cancelled by the requestor. The INT 13
layer uses this to provide a global timeout on all INT 13 calls,
with the result that an unexpected passive failure mode (such as
an iSCSI target ACKing the request but never sending a response)
will lead to a timeout that gets reported back to the INT 13 user,
rather than simply freezing the system.
o INT 13,00 (reset drive) is now able to reset the underlying block
device. INT 13 users, such as DOS, that use INT 13,00 as a method
for error recovery now have a chance of recovering.
o All block device commands are tagged, with a numerical tag that
will show up in debugging output and in packet captures; this will
allow easier interpretation of bug reports that include both
sources of information.
o The extremely ugly hacks used to generate the boot firmware tables
have been eradicated and replaced with a generic acpi_describe()
method (exploiting the ability of iPXE interfaces to pass through
methods to an underlying interface). The ACPI tables are now
built in a shared data block within .bss16, rather than each
requiring dedicated space in .data16.
o The architecture-independent concept of a SAN device has been
exposed to the iPXE core through the sanboot API, which provides
calls to hook, unhook, boot, and describe SAN devices. This
allows for much more flexible usage patterns (such as hooking an
empty SAN device and then running an OS installer via TFTP).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
EFI provides a copy of the SMBIOS table accessible via the EFI system
table, which we should use instead of manually scanning through the
F000:0000 segment.
We have EFI APIs for CPU I/O, PCI I/O, timers, console I/O, user
access and user memory allocation.
EFI executables are created using the vanilla GNU toolchain, with the
EXE header handcrafted in assembly and relocations generated by a
custom efilink utility.
